Rotatable die changer



A ril 9, 1963 E. T. VOGEL 3,084,810

ROTATABLE' DIE CHANGER Filed July 28, 1960 5 Sheets-Sheet 1 April 9, 1963 E. T. VOGEL 3,084,810

ROTATABLE DIE CHANGER Filed Ju1y 28; 1960' 5 Sheets-Sheet 2 INVENTOR E RIC T. VOGEL BYWWW ATTORNEYS E. T. VOGEL V 3,084,810

ROTATABLE DIE CHANGER April 9, 1963 5 Sheets-Sheet 3 Filed July 28, 1960 ATTORNEYS April 9, 1963 E. r. VOGEL ROTATABLE DIE CHANGER 5 Sheets-Sheet 4 Filed July 28. 1960 6. RMW 5 m 00 m m M w. o m w W m R A I E l5 s m w 7 .w flit i1! Mi .4 0%. m 6 J M M 7 V\ at k A h 2 l|i|!||:Ll m

April 9, 1963 E. 'r. VOGEL ROTATABLE DIE CHANGER 5 Sheets-Sheet 5 Filed July 28, 1960 ":4 owwmmmmzoo INVENTOR E RIC T- VOGEL ATTORNEY 3,084,810 7 ROTATABLE DIE CHANGER Eric T. Vogel, 4237 Hampton St, Elmhurst, N.Y. Filed July 28, 1960, Ser. No. 45,829 4 Claims. (Cl. 214-1) to the desired cross-sectional shape of the extrusion to be produced.

A conventional extrusion press consists of a front platen and a rear platen or cylinder crosshead held in fixed relationship by tie rods. A billet container is mounted between the platens and is adapted to move toward and away from the forward platen. A movable crosshead supports a ram adapted to project into the billet container and force a billet therein to flow through the die. The die is mounted in a die carrier which is laterally movable on the face of the forward platen to move the die into and out of register with the exit end of the billet container and an opening through the forward platen through which the extruded shapes leave the press. The die carrier can be either a turret or slide type. However, I prefer to use the slide type.

When an extrusion is to be made, a die holder and die assembly is mounted on the rear face of the die carrier and the latter is moved into a position coaxial with the billet container passage and the billet container is moved forward into contact with the die holder. After a heated billet has been loaded into the container, the ram is moved forwardly under very high pressure to force the billet outwardly through the die. The extrusions are then severed and conveyed away from the press.

The extrusion operation takes place at high temperatures. For example, the extrusion of steel takes place at temperatures between 2200 to 2300 F. The hot metal passing through the die of the press heats the die and causes the surfaces over which it passes to wear rapidly with the result that the dies must be changed periodically. A new die is sometimes needed for the extrusion of each billet in the extrusion of steel.

Therefore, following several extrusions or each extrusion, the die carrier is retracted from its extrusion position on the face of the platen and the die assembly is removed from the carrier to a work or processing station where the die is checked, cleaned and lubricated for reuse.

Upon removal of the used die from the carrier, a new die is placed in the carrier for the next extrusion. The die assembly comprises a holder ring, a backing ring and the die which may in all weigh in excess of 40 pounds. At fast rates of operation, the die assembly must be lifted from the press, transported to the work station, and a new die placed in the carrier, often in the time of one minute or less.

The manual changing of dies, even with suitable hand tools, asbestos gloves and the like, is time consuming and difficult to accomplish in the short time available. Moreover, the work is made arduous by the elevated temperature of the die and press. Due to the weight of the di and the frequency of changes the manual operation is highly fatiguing.

It is an object of this invention to provide a turntable working component transport means suitable for use with an extrusion press or other metal working apparatus for conveying a working component from one station to another while simultaneously delivering a working component to said first station.

3,684,819 Patented Apr. 9, 1963 It is another object of this invention to provide a transport means for use with an extrusion press which is compact and permits dies to be changed rapidly and efficiently with a minimal interruption in the operation of the press and with an increase in the output of extruded products therefrom.

Yet another object of this invention is to provide a transport means for use with an extrusion press, which mechanically removes a die from the press and places it in a location in which it can cool, be visually inspected with convenience, lubricated and otherwise serviced while simultaneously delivering a different die into the die carrier for subsequent movement into extrusion position in the press.

Still another object of this invention is to provide a semi automatic transport means for use with an extrusion press which, in sequence, mechanically removes a used die from the press while simultaneously returning a new die into the die carrier of the press, and which places the used die in a location in which it can be conveniently inspected and lubricated or repaired or discarded, while simultaneously delivering the new die into the die carrier of the press.

These and other objects of my invention will become apparent as the description thereof proceeds.

In its preferred embodiment, my invention comprises a turnable device on a rotatable hollow vertical shaft having a head at the top on which three buckets are equally spaced around the periphery of the shaft. This shaft is mounted on a fixed hollow vertical post about which it rotates. Each bucket has vertical sides and is open at its outer edge to receive a die and hold it in a vertical position in the bucket. Each bucket also has a kicker arm for ejecting a die from the bucket. A vertical rod is positioned within the fixed hollow vertical post and is adapted to move vertically without rotational movement. At the top of the shaft a kicker head is mounted above the buckets which with kicker rollers contact the kicker arms in two buckets simultaneously when the rod is moved in a downward direction by a fluid motor.

The rotating bucket shaft carries a rachet wheel which meshes with a pawl carried on a freely moving gear mounted immediately below and concentric with the ratchet. The free gear meshes with a driving gear mounted on the vertical shaft of an actuator which is an oscillating type hydraulic motor which rotates the driving gear through a specified angle of arc. The vertical shaft of the hydraulic motor also carries a cam which is adapted to operate limit switches at each limit of oscillation which control the operation of the actuator and the limits of rotation.

The lower end of the rotating shaft also carries a memher having three equally spaced prongs around the periphery thereof and which makes contact with a fluid motor actuated retractable pin. The actuator is maintained under continuous rotating pressure, so that the shaft rotates when the stop pin is retracted. This arrangement serves to position the buckets, with respect to changing, unloading and loading stations, which will be more completely described later. I

A die ejector arm operated by a fluid motor is provided for removing the die from the die slide and depositing them in the buckets of the turntable turret.

In operation, the buckets are positioned, one at the changing station to receive a used die from the die ejector arm, the second at an unloading station for ejecting a used die at a processing station and the third at a loading station to receive a new die. In changing dies, the die ejector arm is elevated to remove the used die from the die carrier and deposit it in the bucket located at the changing station. A new die has been previously loaded in the bucket at the loading station. The retractable stop pin is then retracted, and the bucket shaft is rotated until the used die is at the unloading station, the new die is at the changing station and an empty bucket is at the loading station, at which time the rotation is stopped by the prongs at the base of the rotating shaft coming into contact with a stop pin. The vertical rod is then operated to depress the kicker head which strikes the kicker arms in the two buckets at the changing and unloading stations and ejects the new die into the die carrier in the die slide, and the die at the unloading station. The die ejected at the unloading station is conveyed by a chute to a work table where it may be processed, i.e., inspected, cleaned, lubricated, etc. The work table is located adjacent the loading station and after processing, the processed die or a new die may be loaded into the empty bucket. The above operation may then be repeated after another extrusion.

Thus, my invention makes it possible to change dies rapidly with the only manual work being at a station remote from the extrusion press. The device moreover, takes up little space.

A preferred embodiment of my turntable device and the method of operation are illustrated in the accompanying drawings in which like reference numerals refer to like parts.

In the drawings:

FIGS. 1 and 2 illustrate diagrammatic plan views in different positions of my turntable showing the platen of an extrusion press and the die processing and unloading stations,

FIG. 3 illustrates a plan view of the turntable,

FIG. 4 illustrates a modified perspective view with parts in section of the turntable and shows also parts of the die slide and extrusion press platen,

FIG. 4A illustrates the turntable device on a reduced scale and in elevation showing the location of its base with reference to the extrusion press platen,

FIG. 5 is a sectional plan view of the turntable taken along the lines 5-5 of FIG. 6, illustrating the gearing, ratchet and shaft arrangements,

FIG. 6 is a sectional elevation view taken along the lines 66 of FIG. 5, of the lower part of the turntable shaft, showing the shafts, gearing and ratchet, and mounting of the shafts and actuator,

FIG. 7 is a diagrammatic view in elevation of my turntable device showing the elements of the turntable, the die ejector arm and the connecting lines and valves for operating the fluid (compressed air) motors and the hydraulic actuator, I

FIG. 8 is an enlarged scale cross sectional view along the line 88 of FIG. 6 of the hydraulic actuator.

The construction of the turntable will be understood by referring more particularly to FIGS. 3 and 4 of the drawings which illustrate the turntable in elevation and top views. In FIG. 4, the location of the turntable with respect to the extrusion press platen is shown. The vertical shaft of the turntable has been illustrated, however, as broken and'the base of the turntable (comprising the frame, gears, etc.) has been moved up for better showing. In actuality, the turntable base is located at the floor level as shown in FIG. 4A.

In FIG. 4 a portion of the forward platen P of the press showing one tie rod T and the die slide S are shown. The die slide S slides back and forth on the face of the platen in die slide holders R secured on the face of the platen and the center line of the press and die extrusion opening through the platen is indicated at Q.

The turntable is mounted on a frame 1 which may have a substantially rectangular box shape consisting of four vertical sides and top and bottom plates and a hollow vertical post 2 which is inserted into an opening in the top plate of frame 1 and rigidly fixed by welding or other suitable means. A circular stepped bearing plate 3 (FIG. 6) fits around post 2 and rests on and is held against rotation on the top plate of frame 1 by pin '4.

Rotatable head 5, comprising three buckets 5A, 5B and 50, connected by angle members 5D (FIGS. 3 and 4) is secured to the upper end of hollow vertical shaft 6 which fits around post 2. Buckets 5A, 5B and 5C are spaced apart around the periphery of shaft 6. Bushings 7 are mounted in the upper and lower ends of shaft 6. A triangular shaped flange 8, having prongs 9 spaced 120 apart is welded on the shaft 6 at the base thereof. Each prong 9 has an adjustable screw 10 provided with lock nuts and passing therethrough tangent to the rotational direction of the prongs 9.

A boss 11 with a double acting fluid motor 12 attached thereto is mounted on one side of frame 1. Fluid motor 12 is preferably an air cylinder and piston, but a solenoid and piston could be used in place of the fluid motor 12. The fluid motor 12 raises and lowers a stop pin 13. Screws 10 engage stop pin 13 when in its raised position to stop rotation of the shaft 6 at specified positions.

An oscillating actuator 14 is also mounted at the side of frame 1 (see FIGS. 5 and 6 for relative positions). Actuator 14 is preferably a hydraulic motor having a rotatable vertical shaft 14b (FIG. 8) which may be turned in either direction through an angle of about 270 by the act-ion of pressure from a hydraulic fluid on either side of a vertical vane 14A attached to the vertical shaft 14b within the actuator. Actuators of this type are known in the art and described in U.S. Patents Nos. 2,540,903 and 2,793,623. The actuator structuresv do not form a part of the novelty of this invention. A cam 15 (FIGS. 5 and 6) is secured to the lower end of the shaft 14B of actuator 14. Cam 15 rotates with the actuator shaft and makes contact at each extreme of notation with limit switches 16 and 17 mounted on the side of frame 1. In FIG. 5 limit switches 16 and 17 have been illustrated as of a toggle type with toggle arms 16a and 17a, and cam 15 is shown at the limit of its counterclockwise movement and in contact with switch 16. On reversal of the motor .14- the cam 15 will be rotated clockwise through an angle of 240 where it will contact limit switch 17. In place of toggle type limit switches push button switches, mounted on the side of casing 1 may be used.

The upper end of shaft 14]; of actuator 14 carries a pinion 19 which meshes with gear 20. Gear 20' is mounted on the stepped bearing plate 3, around post 2, and rotates freely with respect to bearing plate 3' and post 2. A pawl 21 is mounted on the upper surface of gear 20 by pin 22. Pawl 21 engages a ratchet wheel 24 secured to the lower end of shaft 6 by pin 25. Ratchet wheel 24 rests on the top :of stepped bearing plate 3. Pawl 21 is kept in engagement with ratchet Wheel 24 by the pressure of spring 23 mounted on gear 20.

A rod 27 passes through hollow vertical post 2 and extends above rotatable head 5. The lower end of rod 27 is attached at 27a to the piston of a double acting fluid motor 26, of a type similar to fluid motor 12, for raising and lowering shaft 27. A guide key 28 (FIG. 4) is attached to post 2 and engages an elongated slot in rod 27 to prevent rotation of the rod in post 2 while permitting longitudinal movement of the rod 27 in post 2. A kicker head 29 is mounted on top of rod 27 by screw 30, and is prevented from rotating relative to rod 27 by a key 31 (FIG. 3) held in place by Screw 30.

Kicker head 29 carries two kicker rollers 39 which make contact with kickers 33A, 3313 or 33C, in buckets 5A, 5B or 50 respectively to eject dies from the said buckets. The kickers 33A, 33B and 33C are mounted on pivots 35 in the buckets 5A, 5B and 5C and consist of curved ejector arms 45' which eject the dies from the buckets, straight contact arms 46 which are depressed by kicker head 29, to swing the kickers 33A, 33B or 33C around the pivots 35 and adjustable counter weight members 47 to return the kickers to their position inside the buckets 5. Wear plates 34 are provided on the arms 46. The two contact rollers 39 (see FIG. 3) on kicker head 29 are intended to depress the straight arms 46 of the kickers in the buckets positioned at the changingand discharging stations to move the curved arms 45 from the full line position to the dotted line position 45 shown in FIG. 4 to eject the dies from these buckets. The kicker in the bucket at the loading station is thus not operated and remains in the bucket which is at this station, so that a fresh die can be loaded into the bucket at the loading station.

A die remover arm 36 is provided adjacent the extrusion press for removing a die from the die slot3 7 in the die slide S slidable on the face 38 of the platen P. Arm 36 is attached to crank 36A (FIG. 3) and is operated by fluid motor 40 (see FIG. 7) which is of a type similar to fluid motors 12 and 26, and which operates arm 3613 which is attached to the opposite end of crank 36A. Crank 36A and fluid motor 40 may be mounted on a bracket 36C which may in turn be mounted either on the side of the extrusion press platen P or on the turntable base. In FIG. 4, as previously explained, thebase of the turntable has been shown in a raised position relative to the extrusion press platen due to space limitations in the drawing. Thus, in this figure arm 36' is shown as overlapped by the base. In actuality, the base is'below the remover arm 36 positioned at the floor level, as illustrated in FIG. 4A, and the remover arm 36 is positioned immediately below and in front of the die slot 37, when the die slide is in its retracted position.

The operation of the turntable may be better understood by referring to FIGS. 1, 2 and 7.

In FIGS. 1 and 2, the location of the turntable head 5, die loading station 50 and die remover arm 36 is shown with respect to the extrusion press platen 51 and discharge chute 49. In FIG. 1, bucket 5A is at loading station 50, bucket SE at the die changing station and bucket 50 at the unloading station opposite chute 49'. Directional arrows show movement of dies during operation of the changer. One die is in operating psition in the press. A readied die (either new or cleaned) will manually be placed in bucket 5A. Buckets 5B and 5C are empty at this time.

When a billet has been extruded and a die change is desired, the die slide S is shifted to its inoperative position adjacent the die changer and the die remover arm 36 is actuated by depressing a pushbutton, not shown, to actuate solenoid 41A to move air valve 41 from its rest position (FIG. 7) into position to cause fluid motor 40 to move ejector arm 36 upwardly and lift the used die out of the horseshoe shaped die slot 37 (FIG. 4). The used die will first roll or slide along the horseshoe shaped die slot 37 but when ejector arm 36 reaches the position indicated in dotted lines at 36' in FIG. 4, the used die will roll into bucket SE at the changing station and against a buffer plate 18 (FIG. 3) located at the side of the kicker member 45, the kicker member 45 being in the full line rest position shown in the section in FIG. 4.

The abovementioned push button also actuates a timer not shown, having three contacts. The first contact of the timer energizing solenoid 42A to move valve 42 from the rest position shown, to the right in FIG. 7, to connect the compressed air line 51 with the top opening in fluid motor cylinder 12 to pull stop pin 13 down for a predetermined time, e.g., one second. Actuator 14 which has been under hydraulic pressure from oil line 52 is now free to turn from an initial position shown in chain lines at 14A in FIG. 7 through 240 until it reaches a stroke limit position substantially as indicated in full lines at 14A in FIG. 7 and, as shown, cam 15 engages limit switch 16, the action of which is described subsequently. Pinion 19 moves with actuator 14 and turns gear 20 through 120' since the gear ratio is l to 2. At the same time pawl 21 pushes ratchet wheel 24 which actuates the rotatable shaft 6 with head 5 through 120'. The position of these parts at the end of the turntable movement is indicated in FIG. 7. After a predetermined time delay, the timer deenergizes solenoid 42A and spring actuated valve 42 shifts so as to cause pin 13' to be raised by fluid motor 12. Since pin 13 has returned to its upper position, head 5 will be stopped when the screw 10 of prong 9 aligned with bucket 5A having the ready die therein is at the changing station, bucket 5B having the used die therein is at the unloading station, and the empty bucket 5C is at the loading station. FIG. 2 illustrates the rotatable head 4 as it is turning to these positions.

The second contact ofthe aforementioned timer now energizes solenoid 44A which controls air valve 44 to cause fluid motor 26 to pull rod 27 and kicker head 29 down. Rolls 39actuate the kicker members 33A and 333 so as to move them to the dotted line position indicated at 45 in FIG. 4. As compared with FIG. 1, bucket 5A is now at the changing station where formerly 5B was located and bucket 5B is at the unloading station. The readied die will be moved from bucket 5A onto the ejector arm 36 and the used die ,will be discharged from bucket 5B into' chute 49 through which it rolls to a processing station.

The third contact of the timer deenergized solenoid 41A which shifts air valve 41 and causes the fluid motor 40 to lower the ejector arm 36 with the ready die thereon, the latter being received in slot 37 of the die slide.

After apredetermined delay, the second contact deenergizes solenoid 44A to move air valve 44 so that fluid motor 26 is reversed and kicker head 29 is moved upwardly and the kicker members 33A and 33B return to their initial retracted positions in the buckets 5A and 513 under the action of gravity and counterweights 47.

A new or cleaned die may be inserted manually in the empty bucket 5C at the loading station at any time after the latter has reached the loading station.

As previously indicated, cam 15 which is originally in the chain line position 15, contacts limit switch 16 at the end of the forward stroke of actuator 14. The switch 16 which energizes solenoid 43A, controlling hydraulic valve 43, will then cause reversal of the actuator 14 so that the latter will return to its initial position. During this movement, pinion B19 moves gear 20 along which turns freely on its bearing plate 3. Pawl 21 will slide over the ratchet teeth of wheel 24 without causing it to move, due to inertia and friction in the mechanism connected to the wheel. Any slight turning would be corrected when the actuator is under forward pressure again. However, a locking pawl, as well known in ratchet mechanism, may be used if desired. When the actuator 14 completes its return stroke, cam 15 will reach its chain line position 15 again and engage limit switch 17. This will operate solenoid 43A to reverse hydraulic valve 43 and cause the actuator 14 to be connected to forward pressure again. However, the actuator cannot move forward now since pawl 21 engages ratchet wheel 22, and one of the screws 10 in prongs 9 engages stop pin 13. The next die changing cycle is started when the push button for the die ejector arm is depressed again.

While I have described a specific embodiment of my invention and preferred mode of operation in detail, it will be understood that this is solely for the purpose of illustrating the invention and enabling persons skilled in the art to better understand and practice the invention.

There is no intention to limit the invention to the embodiment described, and various changes and modifications may be made from the structure illustrated without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Transport means for transferring a used die between an extrusion press and a processing station and placing a new die in said press, comprising in combination a vertical rotatable shaft having three buckets mounted thereon and substantially equally spaced around the upper end of said shaft for holding dies, said buckets being indexed step-bystep sequentially between loading, changing, and unloading stations respectively which are substantially equally spaced around the periphery of said buckets, support means for said shaft, means at said changing station to lift said used die from said extrusion press to the bucket at said changing station, an ejector in each of said buckets, said ejector having means for biasing same into inoperative position and means for actuating said ejectors to eject the used die at the unloading station and a new die at the press changing station; a vertically movable camming member extending over the changing station and the unloading station and operable upon vertical movement to operate said actuating means to eject the dies at the changing stations and unloading stations while leaving the ejector in the loading station inoperative, whereby a new die is loaded into a bucket at the loading station and a used die is loaded into a bucket at the changing station, the buckets being rotated substantially 120, and a new and used die ejected at the changing and unloading stations respectively while the ejector at the load station is maintained in inoperative position by the biasing means.

2. Transport means for transferring a used die between an extrusion press and .a processing station and placing a new die in said press, comprising in combination a vertical rotatable shaft having three buckets mounted thereon and substantially equally spaced around the upper end of said shaft for holding dies, said buckets being indexed step-by-step sequentially between loading, changing, and unloading stations respectively which are substantially equally spaced around the periphery of said buckets, ejection means in each of said buckets, support means for said shaft, means at said changing station to lift said used die from said extrusion press to the bucket at said changing station, an ejector in each of said bucket, said ejector having means for biasing same into inoperative position and means for actuating said ejectors to eject said used die at the unloading station and said new die at the press changing station; a vertically movable camming member extending over the changing station and the unloading station and operable upon vertical movement to operate said actuating means to eject the dies at the changing stations and unloading stations while leaving the ejector in the loading station inoperative, means to impose a rotating force on said shaft, stop means on said shaft to control rotation thereof, and a stop pin retractable from and engageable with said stop means on said shaft to permit rotation and to halt rotation of said shaft with said buckets aligned with said stations, whereby a new die is loaded into a bucket at the loading station and a used die is loaded into a bucket 8 at the changing station, the buckets being rotated substantially and a new and used die ejected at the changing and unloading stations respectively while the ejector at the load station is maintained in inoperative position by the biasing means.

3. The transport. means of claim 2 comprising fiuid power means and indexing means for sequentially performing the steps of loading a used die from said extrusion press in a bucket, rotating said shaft substantially 120, ejecting said used die at an unloading station while simultaneously ejecting a new die to said extrusion press.

4. Transport means for transferring a used metal die between a metal extrusion press and a processing station and placing a new metal die in said press, comprising in combination a vertical rotatable shaft having three buckets mounted thereon and substantially equally spaced around the upper end of said shaft for holding dies, said buckets being indexed step by-step sequentially between loading, changing, and unloading stations respectively which are substantially equally spaced around the periphery of said buckets, ejection means in each of said buckets, support means for said shaft, means at said changing station to lift said used die from said extrusion press to the bucket at said changing station, an ejector in each of said buckets, said ejector having means for biasing same into inoperative position and means for actuating said ejectorsto eject said used die at the unloading station and said new die at the press changing station; a vertically movable camming member extending over the changing station and the unloading station and operable upon vertical movement to operate said actuating means to eject the dies at the changing stations and unloading stations While leaving the ejector in the loading station inoperative, whereby a new die is loaded into a bucket at the loading station and a used die is loaded into a bucket at the changing station, the buckets being rotated substantially U20, and a new and used die ejected at the changing and unloading stations respectively while the ejector at the loading station is maintained in inoperative position by the biasing means.

References Cited in the file of this patent UNITED STATES PATENTS 2,095,960 Bach Oct. 19, 1937 2,634,002 Paul Apr. 7, 1953 2,941,665 Weston June 21, 1960 2,953,233 Zurheide Sept. 20, 1960 2,963,151 Kent Dec. 6, 1960 

1. TRANSPORT MEANS FOR TRANSFERRING A USED DIE BETWEEN AN EXTRUSION PRESS AND A PROCESSING STATION AND PLACING A NEW DIE IN SAID PRESS, COMPRISING IN COMBINATION A VERTICAL ROTATABLE SHAFT HAVING THREE BUCKETS MOUNTED THEREON AND SUBSTANTIALLY EQUALLY SPACED AROUND THE UPPER END OF SAID SHAFT FOR HOLDING DIES, SAID BUCKETS BEING INDEXED STEP-BYSTEP SEQUENTIALLY BETWEEN LOADING, CHANGING, AND UNLOADING STATIONS RESPECTIVELY WHICH ARE SUBSTANTIALLY EQUALLY SPACED AROUND THE PERIPHERY OF SAID BUCKETS, SUPPORT MEANS FOR SAID SHAFT, MEANS AT SAID CHANGING STATION TO LIFT SAID USED DIE FROM SAID EXTRUSION PRESS TO THE BUCKET AT SAID CHANGING STATION, AN EJECTOR IN EACH OF SAID BUCKETS, SAID EJECTOR HAVING MEANS FOR BIASING SAME INTO INOPERATIVE POSITION AND MEANS FOR ACTUATING SAID EJECTORS TO EJECT THE USED DIE AT THE UNLOADING STATION AND A NEW DIE AT THE PRESS CHANGING STATION; A VERTICALLY MOVABLE CAMMING MEMBER EXTENDING OVER THE CHANGING STATION AND THE UNLOADING STATION AND OPERABLE UPON VERTICAL MOVEMENT TO OPERATE SAID ACTUATING MEANS TO EJECT THE DIES AT THE CHANGING STATIONS AND UNLOADING STATIONS WHILE LEAVING THE EJECTOR IN THE LOADING STATION INOPERATIVE, WHEREBY A NEW DIE IS LOADED INTO A BUCKET AT THE LOADING STATION AND A USED DIE IS LOADED INTO A BUCKET AT THE CHANGING STATION, THE BUCKETS BEING ROTATED SUBSTANTIALLY 120*, AND A NEW AND USED DIE EJECTED AT THE CHANGING AND UNLOADING STATIONS RESPECTIVELY WHILE THE EJECTOR AT THE LOAD STATION IS MAINTAINED IN INOPERATIVE POSITION BY THE BIASING MEANS. 